<template>
    <el-container id="home-container">
        <!-- 头部区域 -->
        <el-header>
            <div>
                <img src="../assets/heima.png" title="电商后台管理系统">
                <span>电商后台管理系统</span>
            </div>
            <el-button type="info" @click="logout">退出</el-button>
        </el-header>
        <!-- 页面主体区域 -->
        <el-container>
            <!-- 侧边栏 -->
            <el-aside :width="isCollapse ? '64px' : '200px'">
                <!-- 侧边栏菜单区域 -->
                <!-- active-text-color="#ffd04b" 激活的文本值 -->
                <!-- unique-opened  点击当前的菜单 其余的菜单不展开  默认值是true 也可以写成:unique-opened="true" -->
                <!-- :router="true" 为每个二级菜单绑定子路由 -->
                <el-menu background-color="#333744" text-color="#fff" active-text-color="#409eff" unique-opened
                    :collapse="isCollapse" :collapse-transition="false" :router="true" :default-active="activePath">
                    <div class="toggle-button" @click="toggleCollapse">|||</div>
                    <!-- 这是一级菜单 -->
                    <!-- :index="item.id + ''"  我们的item.id是动态获取的  但是e-ui认定原先的index是一个字符串  所以拼接一个空的字符串 让他编程一个字符串 -->
                    <el-submenu :index="item.id + ''" v-for="item in menulist" :key="item.id">
                        <!-- 一级菜单的模板区域 -->
                        <template slot="title">
                            <!-- 图标 -->
                            <i :class="iconObj[item.id]"></i>
                            <!-- 文本 -->
                            <span>{{ item.authName }}</span>
                        </template>
                        <!-- 这是二级菜单 -->
                        <!-- :index="'/' + subItem.path + ''"  因为我的父级菜单是绑定了router的，所以里面的子菜单的跳转项是根据index -->
                        <el-menu-item :index="'/' + subItem.path + ''" v-for="subItem in item.children"
                            :key="subItem.id" @click="saveNavState('/' + subItem.path + '')">
                            <!-- 图标 -->
                            <i class="el-icon-menu"></i>
                            <!-- 文本 -->
                            <span>{{ subItem.authName }}</span>
                        </el-menu-item>
                    </el-submenu>
                </el-menu>
            </el-aside>
            <!-- 右侧内容主体 -->
            <el-main>
                <!-- 放一个路由占位符 -->
                <router-view></router-view>
            </el-main>
        </el-container>
    </el-container>
</template>

<script>
export default {
    data() {
        return {
            // 左侧菜单数据
            menulist: [],
            iconObj: {
                125: 'iconfont icon-user',
                103: 'iconfont icon-tijikongjian',
                101: 'iconfont icon-shangpin',
                102: 'iconfont icon-danju',
                145: 'iconfont icon-baobiao'
            },
            // 是否折叠
            isCollapse: false,
            // 被激活的链接地址
            activePath: ''
        }
    },
    created() {
        this.getMenuList()
        this.activePath = window.sessionStorage.getItem('activePath')
    },
    methods: {
        logout() {
            window.sessionStorage.clear()
            this.$router.push('/login')
        },
        // 获取所有的菜单
        // 因为我的get请求返回的是一个promise对象  所以要写 async 和 const { data: res } = await  将其变成一个data对象
        async getMenuList() {
            const { data: res } = await this.$http.get('menus')
            if (res.meta.status !== 200) return this.$message.error(res.meta.msg)
            this.menulist = res.data
            // console.log(res)
        },
        // 点击按钮切换菜单的折叠与展开
        toggleCollapse() {
            this.isCollapse = !this.isCollapse
        },
        // 保存链接激活的激活状态
        saveNavState(activePath) {
            window.sessionStorage.setItem('activePath', activePath)
            this.activePath = activePath
        }
    }
}
</script>

<style lang='less' scoped>
#home-container {
    height: 100%;
    user-select: none;
}

.el-header {
    background-color: #373d41;
    display: flex;
    justify-content: space-between;
    padding-left: 0;
    align-items: center;
    color: #fff;
    font-size: 20px;

    >div {
        display: flex;
        align-items: center;

        img {
            width: 20%;
        }

        span {
            margin-left: 15px;
        }
    }
}

.el-aside {
    background-color: #333744;

    .el-menu {
        border-right: 0;
    }
}

.el-main {
    background-color: #eaedf1;
}

.iconfont {
    padding: 0 10px 0 3px;
    text-align: center;
}

.toggle-button {
    background-color: #4a5064;
    text-align: center;
    font-size: 10px;
    line-height: 24px;
    color: #fff;
    cursor: pointer;
    // 字与字之间的距离
    letter-spacing: 0.2em;
    user-select: none;
}
</style>
